In May 2007, resolution WHA60.1 of the World Health Assembly requested the Director‐General of the World Health Organization (WHO) to undertake a major review, in 2010, of the state of smallpox research

End Of Vaccination Took Away Protection From HIV, Say Researchers
Washington: The end of smallpox vaccination in the mid-20th century could be responsible for a loss of protection that led to the rapid spread of HIV, according to researchers.
It is known that vaccinia immunization, as given to prevent the spread of smallpox, reduces HIV replication in the laboratory.